imconfig.h
USE_EXTERNAL_FONT

Use canvas2d fillText to generate the fonts that used at runtime. 

Use overlay document element 'input' for single line text, and 'textarea' for multi-line text input.
We can input text from mobile now.

TODO InputInt and other function input from mobile

When window is no_move, we can slide content then HoveredID=0. Usefull for mobile with no mouse wheel.

download and install [Emscripten](http://kripken.github.io/emscripten-site/docs/getting_started/downloads.html)
cd imgui-ts/imgui/embind
make

cd imgui-ts
npm install
webpack

import {ImGui, ImGui_Impl} from '@zhobo63/imgui-ts'

let text:ImGui.ImStringBuffer=new ImGui.ImStringBuffer(128,'input text');
let text_area:ImGui.ImStringBuffer=new ImGui.ImStringBuffer(128,'edit multiline');

function _loop(time:number):void {
    ImGui_Impl.NewFrame(time);
    ImGui.NewFrame();
    ImGui.Begin("Hello");
    ImGui.Text("Version " + ImGui.VERSION);
    ImGui.InputText("Input", text);
    ImGui.InputTextMultiline("Text", text_area);
    ImGui.End();
    ImGui.EndFrame();
    ImGui.Render();

    ImGui_Impl.ClearBuffer(new ImGui.ImVec4(0.25,0.25,0.25,1));
    ImGui_Impl.RenderDrawData(ImGui.GetDrawData());
    window.requestAnimationFrame(_loop);
}

window.addEventListener('DOMContentLoaded', async () => {
    await ImGui.default();

    ImGui.CHECKVERSION();
    ImGui.CreateContext();
    const io:ImGui.IO=ImGui.GetIO();
    ImGui.StyleColorsDark();
    io.Fonts.AddFontDefault();

    const canvas:HTMLCanvasElement=document.getElementById("canvas") as HTMLCanvasElement;
    ImGui_Impl.Init(canvas);
    window.requestAnimationFrame(_loop);
});